#pragma once

#ifndef HAVE_FAUDIO
#error "FAudio support disabled but still being built."
#endif

#include "Emu/Audio/AudioBackend.h"

#include "FAudio.h"

class FAudioBackend final : public AudioBackend, public FAudioVoiceCallback, public FAudioEngineCallback
{
public:
	FAudioBackend();
	~FAudioBackend() override;

	FAudioBackend(const FAudioBackend&) = delete;
	FAudioBackend& operator=(const FAudioBackend&) = delete;

	std::string_view GetName() const override
	{
		return "FAudio"sv;
	}

	bool Initialized() override;
	bool Operational() override;

	bool Open(std::string_view dev_id, AudioFreq freq, AudioSampleSize sample_size, AudioChannelCnt ch_cnt, audio_channel_layout layout) override;
	void Close() override;

	f64 GetCallbackFrameLen() override;

	void Play() override;
	void Pause() override;

private:
	static constexpr u32 INTERNAL_BUF_SIZE_MS = 25;

	FAudio* m_instance{};
	FAudioMasteringVoice* m_master_voice{};
	FAudioSourceVoice* m_source_voice{};

	std::vector<u8> m_data_buf{};
	std::array<u8, sizeof(float) * static_cast<u32>(AudioChannelCnt::SURROUND_7_1)> m_last_sample{};

	atomic_t<bool> m_reset_req = false;

	// FAudio voice callbacks
	static void OnVoiceProcessingPassStart_func(FAudioVoiceCallback* cb_obj, u32 BytesRequired);

	// FAudio engine callbacks
	static void OnCriticalError_func(FAudioEngineCallback* cb_obj, u32 Error);

	void CloseUnlocked();
};
